so I broke the daily

Massive misfires, won't idle without foot on the gas, blinking cel when running.

Honestly from the drivers seat it feels like it jumped timing.

Just prior to this, leaving stoplights, it felt almost like fwd tire spin. I know it was a bog in carb terms, but didn't feel like one. Just like tire slip over a slushy patch of road, then grip and go.

Car is a 2002 protege5 automatic. 168k. Supposedly had timing belt at 90k.

Kicking codes p302 and p1250. Cyl 2 and a fuel pressure regulator sensor.

Not speaking Japanese fwd, where do I start diagnosis? Its a wasted spark setup, so if it was a coil, 2 cylinders would be dead.

Problems just started today, so something failed is the only thing I can think of. And throwing parts at it is not an option. Don't have the money for that. Want to figure out exactly what broke, fix it, and move on with my life.

Currently driving the elky, so I have a few days to work at it.

I would start by checking/swapping injectors (if fairly easy). Other than mechanical failure, the injector(s) would be the next common failure if a misfire is in a specific cylinder. Plus you have a fuel system/pressure code, so could be related.

Swap plugs/wires with a good cylinder. You should be able to hear the injectors click with a screwdriver or similar tool.

Dusterbd13 wrote: Its a wasted spark setup, so if it was a coil, 2 cylinders would be dead.

Not necessarily. If it was a low-voltage side fault, then yes, but if the coil is arcing to ground internally then you can have a wasted spark ignition that happily fires one of the plugs.

I just ran across one of these. 2.0l engine, I think the FS, yeah? It's got plug wires, it's a coil on/coil near plug setup.

Can't help with the fuel pressure sensor issue, but if you take the connector off and fuel comes out, then that's a problem :)

Swap the coils around and if the misfire code moves. Work on the misfire first. Definitely don't drive it with a flashing CEL, this kills the cat.

It's new enough to have an OBD-II port. Do you have or can you borrow a scanner? I think some chain auto parts stores will loan them with a deposit. With codes you may be able to find common problems to further investigate on the interwebz and better focus your diagnostic efforts.

Or somebody much smarter than me may post the correct diagnosis in 5 more minutes...

secretariata wrote: It's new enough to have an OBD-II port. Do you have or can you borrow a scanner? I think some chain auto parts stores will loan them with a deposit. With codes you may be able to find common problems to further investigate on the interwebz and better focus your diagnostic efforts. Or somebody much smarter than me may post the correct diagnosis in 5 more minutes...

He posted the codes in the original post...

pointofdeparture wrote: He posted the codes in the original post...

Oops! Reading comprehension fail on my part.

Low fuel pressure isn't going to cause a misfire in just #2. Also, P1250 is, like you stated, a fuel pressure SENSOR malfunction; that means the ECU may not know what the actual fuel pressure is, and is defaulting to theoretical pressure setting, probably on the high side of safe. I am inclined to think those two codes are not directly related to each other. For that matter, the P1250 code may have been stored for quite some time and would not neccesarily trigger a check engine light if the ECU is still able to get the engine to run within it's programmed parameters.

So the two codes are probably not related. I'll treat it as two separate problems. Will try swapping and physical inspection of coils and plugs tomorrow.

But none of you have mentioned checking cam timing. Which makes me happy. Means that my fears of bent valves are probably just irrational fear.

In reply to Dusterbd13:

Nah, if it jumped a tooth it wouldn't misfire. It would run like complete poo until it reached X-rpm then it would take off like scalded cat all the way to redline.

Start reading before you buy anything or make any assumptions... http://www.mazdas247.com/forum/showthread.php?123844648-HELP-Protege5-Low-Idle-and-Misfire

If you jump time bad enough to bend valves you will bend valves on all cylinders, usually the exhausts.

Have you actually checked the timing belt to see if it is still to spec?

have not checked anything. when I posted last night was when I finally got home from work.

today, ill be leaving work early to start in on this. have plug wires coming today, as I have never done them, and have no records of them being done other than the previous owner saying he did when he replaced a coil.

ill start tonight with swapping plug wires/coil tubes, and test. if the problem doesn't change, ill try swapping coils with each other. if the misfire cylinder number changes, then we know its a coil. if it doesn't, then we move on to trying to swap the injectors around and see if it follows the injector. prior to anything, ill pull plug 2 and check for any signs of failure.

correct?

Write down codes - clear codes - run til light comes on - rescan for codes.

While you are checking codes get into the data stream and do a sanity check on sensors.

A temp sensor out of range will not set a code, etc.

Check fuel pressure (under load too).

Use an injector test light to verify ECM triggering.

Swap injectors to verify operation.

Check swap plugs to verify good.

At some point after this you will need a proper diagnostic manual.

http://www.floptical.net/mazda/

found the service manual!!!!

also has a flowchart for the dtc codes. which is great. and pretty much covers all the stuff we've been talking about.

im using an ebay Bluetooth dongle and torque on my smartphone. is there any way to get the freeze frame data off the computer this way?

[URL=http://s54.photobucket.com/user/dusterbd13/media/Mobile%20Uploads/2015-12/20151209_152919_zpsjtssztwu.jpg.html][/URL]

Found the misfire. Spring in the coil boot collapsed. Found odd burn marks on the plug porcelain if the number two plug. New wires and boots were $40.

Destroyed the cat. Rattling and banging ariund now.

Guess I'll do a header or something. Maybe gut it and nonfouler it. Haven't decided yet.

P1250 has not come back yet, but it's only been 4 miles.

Car is down on power. Probably due to the cat, right?

A partially plugged cat will definately kill power, and start to cause other issues in short order. Does your car have a mani-cat?

Drop the exhaust system out and insepct, maybe you just melted the pre cat and the downstream will be ok if you remove the chunks soon. Or it could have all melted down/chunked and plugged the muffler.

Kinda a manicat. Specially made cat that is bolted to the manifold. And eveything is siezed to the point that i cant dissassemble to gut. So ebay longtube it is. Berk.

Dusterbd13 wrote: Kinda a manicat. Specially made cat that is bolted to the manifold. And eveything is siezed to the point that i cant dissassemble to gut. So ebay longtube it is. Berk.

I have yet to lose a fastener fight when using multiple and prodigious applications of PB Blaster, some patience, and a BFH.

Dusterbd13 wrote: Kinda a manicat. Specially made cat that is bolted to the manifold. And eveything is siezed to the point that i cant dissassemble to gut. So ebay longtube it is. Berk.

Can you use a nut splitter?

I'll have to look again. Don't know if it would fit.

They make smaller ones too.